A reflow soldering apparatus solders electronic parts to a substrate while conveying, for example, a printed circuit board on which electronic parts are mounted with a cream solder or the like, through the use of a conveyor in a reflow furnace which has a preliminary heating process, a reflow process, and a cooling process in order (refer to Patent Document 1).
On the other hand, there has been proposed a reflow soldering apparatus which is such that in order to prevent air bubbles generated in a soldered portion during soldering from remaining in the soldering portion, a decompression chamber capable of reducing the atmospheric pressure is provided on a substrate conveyance path so that a soldered portion of a substrate which has been melted by heating is degassed in the decompression chamber (refer to Patent Document 2). This reflow soldering apparatus is configured in such a manner that the decompression chamber has, in the interior thereof, a pair of right and left substrate supporting rails and that the spacing (the rail width) between the pair of substrate supporting rails in this decompression chamber can be changed according to the width of the substrate.
More specifically, the substrate conveying rails which are arranged on the upstream side and the downstream side, with the decompression chamber sandwiched therebetween, are such that at least either of the right and left rails is capable of moving in the width direction. By moving this one of the right and left rails, it is possible to adjust the spacing (the rail width) between the conveying rails in such a manner as to adapt to substrates having different widths.
Also, at least either of the pair of substrate supporting rails in the decompression chamber is capable of moving in the width direction. By moving this one of the substrate supporting rails, it is possible to adjust the spacing (the rail width) between the substrate supporting rails in the decompression chamber in such a manner as to adapt to substrates having different widths.
The substrate supporting rails in the decompression chamber and the substrate conveying rails on the upstream side and downstream side of the decompression chamber are coupled together by a rail coupling mechanism. This rail coupling mechanism connects and disconnects the substrate conveying rails and the substrate supporting rails in synchronization with opening and closing actions of a shutter which performs the opening and closing of the decompression chamber. That is, a closing action of the shutter causes the rail coupling mechanism to disconnect the substrate conveying rails and the substrate supporting rails from each other. On the other hand, an opening action of the shutter causes the rail coupling mechanism to couple the substrate conveying rails and the substrate supporting rails together. When the shutter is open, which brings the substrate conveying rails and the substrate supporting rails into an integral condition, it is possible to simultaneously change the spacing between the right and left substrate conveying rails and the spacing between the right and left substrate supporting rails in the decompression chamber.
However, in the structure shown in Patent Document 2, a shutter structure which performs the opening and closing of the decompression chamber is necessary to cause the rail coupling member to go into action in synchronization with the opening and closing actions of the shutter which performs the opening and closing of the decompression chamber.
Patent Document 1: Japanese Patent Laid-Open No. 2000-188467
Patent Document 2: Japanese Patent Laid-Open No. 2011-171714